/U[ ]symbol /u
These options undefine previously defined symbols. /U undefines the specified symbol. /u undefines all previously defined symbols.
Neither option can undefine symbols created with the #define directive.
/u undefines the following Microsoft-specific macros. /U can undefine these options also.
Symbol | Function |
---|---|
_CHAR_UNSIGNED | Default char type is unsigned. Defined when /J is specified. |
_CPPRTTI | Defined for code compiled with the /GR (Enable Run-Time Type Information) option. |
_CPPUNWIND | Defined for code compiled with the /GX (Enable Exception Handling) option. |
_DLL | Defined when /MD is specified. |
_M_IX86 | 1Defined as 500 for Blend (/GB), 300 for 80386 (/G3), 400 for 80486 (/G4), 500 for Pentium (/G5), and 600 for Pentium Pro, Pentium II, and Pentium III (/G6). |
_MSC_VER | Defines the compiler version. Defined as 1200 for Microsoft Visual C++ version 6.0 or later. Always defined. |
_WIN32 | 1Defined for applications for WIN32. Always defined. |
_MT | Defined when /MD or /MT is specified. |
1 x86 specific
Compiler Options | Setting Compiler Options